The disclosed embodiments relate to a medical device. Specifically, the disclosed embodiments relate to a connection structure for connecting two metal bodies, and a guide wire having the connection structure.
To date, various connection structures for connecting two metal bodies have been proposed, in particular for forming a flexible connected portion.
For example, Japanese Patent Application Laid-Open No. 2000-145660 describes a flexible shaft (a connection structure) in which an axial part is connected to a coupling through a bendable part comprising a coiled spring, the coiled spring being a multi-thread coiled spring (see, e.g., FIG. 1). The coiled spring serves as a connected portion. This enables the connected portion to be flexible.
However, the flexible shaft described in Japanese Patent Application Laid-Open No. 2000-145660 has the following disadvantage: the axial part is connected to the coupling through the entire circumference of the coiled spring, and thus the flexible shaft may be somewhat difficult to bend due to the repulsive force of the coiled spring. Further, if the axial part and the coupling comprise dissimilar metals, this dissimilarity needs to be taken into account when a connected portion is formed.
Moreover, such a connection structure may potentially be used in a medical device, in particular a guide wire which is used inside a complicatedly winding blood vessel.